Bis-adduction products and methods of preparing same



United States Patent 3,153,635 BIS-ADDUCTION PRODUCTS AND METHGDS 0FPREPAG SAME Charles Kezerian, Los Angelles, and William M. Ramsey,.Dovv'ney, Califi, assignors to Sta'utier Chemical Company, acorporation of Delaware No Drawing. Filed Mar. 18, 1959, Ser. No.800,116 28 Claims. (Cl. 260- 329) This invention relates to products,and methods of producing same, from the group consisting of:

. (a) A compound essentially of the formula:

r a r r Z Z wherein Z and Z are the same or different bis-adductionreaction residues of a member of the class consisting of unsaturatedpolycarboxylic acids and salts (includes acid addition salts and saltshaving a cation bonded to a carboxyl group) thereof and R is thesubstituent defined below;

(b) Chelates comprising the product of (a) and a polyvalent metal ion;and

(c) Esters comprising the product of (a) and a lower alkyl substituentbonded to at least one carboxyl group.

Stated in a different manner, this invention relates to bis-adductionproducts, and methods of producing same, from the group consisting of:

(a) A compound essentially of the formula:

BOOC-Rr-Bs Ra-RsCOOB wherein R is a member of the class consisting ofalkylene,

, phenylene -lower alkylene phenylene, lower alkylenephenylene-loweralkylene, and lower alkylene-'NH-lower alkylene groups; and R and R aremembers of the class consistingof hydrogen, lower alkyl groups, -COOBgroups, and lower alkylene-COOB groups; R and R are members of the classconsisting of lower alkylene groups and lower alkylene groups having anadditional free bond; n is a positive .integer of not less than 1 andnot more than 2; R and R are lower alkylene groups when n is 1; R and Rare members of the class consisting of hydrogen, lower alkyl radicals,and lower alkylene- COOB groups; and B in the above formula is the sameor different radical from the class consisting of hydrogen,

organic base radicals, inorganic base radicals, and lower alkylradicals;

(b) Chelates comprising the compound of (a) and a polyvalent metal ion;and

ene groups, respectively. The term carboxyl is herein intended toinclude the fil; o..

ice

lower alkylene-ITI-lower alkylene H radical (a) that is repeated adesired (the term desired may be zero) number of times, (b) wherein eachlower alkylene radical may be the same or diiferent, and (0) whereineach repeating radical need not be the same as the preceding one. The

lower alkylene-I Hower alkylene radical may be illustrated by thefollowing groups:

R and R in the above formula may be hydrogen, a lower alkyl group, alower alkylene-COOB group, or a 'COOB group. R and R are lower alkylenegroups such as methylene or a lower alkylene group having an additionalfree bond; R and R are lower alkylene groups such as methylene. R and Rmay be hydrogen, a lower alkyl radical, or a lower alkylene-COOBradical. B may be the same or diiferent radical from the groupconsisting of hydrogen, an organic base radical'such as triethanolamine,an inorganic base radical such as sodium, or a lower alkyl ester radicalsuch as CH CH Products of the above formulae may be produced by reactingan organic poly primary amine with one mole of an alkali metal ortertiary amine salt of an unsaturated polyoarboxylic acid for eachprimary amine group present in the organic poly primary amine. Theadduction reaction involves a reaction between the nitrogen atoms of theamine and the double bond of the acid, ester, or salt thereof. Thisreaction may be illustrated by the following equation:

where R and R are hydrogen or lower alkyl groups and R and B are'asdefined above. The salts formed in this manner may be converted tothe free amino acids by treatment with stronger acids. In most cases thefree amino acid is precipitated and may be separated by filtram l-o OTcaorn- Q-N112),

Obviously, mixed or unsymmetrical amino acid products may be produced byemploying mixtures of different unsaturated polycarboxylic startingmaterials.

The unsaturated polycarboxylic acids which are suitable for use inproducing the compounds of this invention include aconitic, citraconic,itaconic, maleic, fumaric, methylitaconic, glutaconic, methylglutaconic,muconic acids, and the like, their salts, anhydrides, nitriles, etc.These acids are characterized by the presence of the 1,4 conjugatedmoiety:

Suitable organic poly primary amines include ethylenediamine,diethylenetriamine, tetraethylenepentamine, propylenediamine,hexamethylenediamine, beta hydroxypropylenediamine, 2,2-diaminodiethylether, 2,2'-diaminodiethyl sulfide, phenylenediarnines,2,2',2"-triaminotriethylamine, benzidine, diaminocyclohexane,diaminophenyl, polygylcoldiamine, lysine, ornithin, methylenedianiline,O-aminoethyl aniline, ammeline, melamine, tris-3-aminopropylamine, etc.

Our novel process for the preparation of the adduction products of thepresent invention is accomplished by heating a basic aqueous solution ormelt of the poly primary amine with the unsaturated polycarboxylic acidfor a period of time sufiicient to complete the reaction (from a fewhours to a few days). The molecular proportions of the reactants areapproximately one mole of the unsaturated polycarboxylic acid perprimary amine group present in the poly primary amine. The alkalinity ofthe reaction mixture is established and maintained by means of a stronginorganic base or nonreactive strong organic base. Suitable basesinclude NaOH, KOH, triethylamine, triethanolamine, and the like. Thebasicity of the reaction mixture is preferably held at a pH above 9.5.The speed of the reaction may be varied to some extent by varying thetemperature and pressure conditions under which the reaction is carriedout. In general, the most satisfactory procedure is to heat the mixtureto a refluxing temperature at atmospheric pressure for a period of atleast several hours. It is essential to maintain alkaline reactionconditions during such polyadduction reactions in order to preventunnecessary complex side reactions involving carboxylic hydrogens withexcess amine groups.

a} The following typical examples illustrate the general nature of thenew process and show a variety of hisadducts of diprimary amines withunsaturated polycarboxylic acids.

EXAMPLE I Elhylenediamine Bis-N,N-Succinic Acid CHGOONa CHzNHz A eH-COONa HzNHz HOH -CH2NOH COOH HgCOOH 2 400 grams of maleic anhydride(4.1 moles) were added to 400 ml. water, and the mixture was set asidefor one hour. This mixture was neutralized slowly under a refluxcondenser, while cooling (7585 C.) and stirring during the dropwiseaddition of 700 g. of 50% by Weight NaOH (8.75 moles). Extreme cautionshould be exercised at this stage, since if NaOH accumulates in quantityunreacted in the reaction media, it may suddenly react withnearexplosive violence. However, during this neutralizationhydrolysis,the temperature should not be allowed to drop below 70 C. in order toprevent the separation of sodium maleate.

The hot reaction solution of disodium maleate was treated with 170 g. of70% by weight ethylenediamine (2.0 moles). The solution was thendigested above C., and finally treated under reflux for 48 hours in astainless steel reactor. The final reaction solution 36 B.) was cooledto room temperature, then acidified to a pH of 2.0 with 680 ml. ofconcentrated HCl (8.2 moles). When no further product separates (6-16hours), the white slurry of micro-crystals was filtered, washed withthree, 250 ml. portions of water, and then dried to a constant weight at90100 C. The products melted at 220222 C. and constituted 540 g. yield(92.2% of the theoretical 548 g. yield).

The product, ethylenediamine bis-N,N'-succinic acid (EDDS-4H), was foundto be only slightly soluble in water and insoluble in ethanol, acetone,benzene, and most organic solvents. 0.77 gram of the product dis solvedin ml. of H 0 at 28 C.

A 292 g. (1.0 mole) portion of EDDS-4H was dissolved in 400 ml. of watercontaining g. (4.0 moles) of NaOH. The solution was cooled, andacidified to a pH of 2.0 with 330 ml. of concentrated HCl (4.0 moles).The solution was seeded, and was set aside (undisturbed) for 24 hours,filtered, and then washed with 500 ml. of water. The product was airdried to the dihydrate. Recrystallization yielded 280 g., that is, 85.4%of the theoretical yield of 328 g. The product was divided into twoportions: (A), which was analyzed as such and (B), which was dried to aconstant weight at 90 C. A pentahydrate of EDDS-4H was prepared bypassing boiling water through a pad of EDDS-4H; rapid cooling of theclear filtrate yielded long, transparent needles (C). Analytical datahave confirmed the samples as:

(A) EDDS-4H-2H O (B) EDDS4H, anhydrous (C) EDDS-4H-5H O Molecular weightdetermined by pH titration:

(B) C10H1 NgO found 290, theory 292; inflections at pH of 5.5, 8.7 and11.25.

(C) C H N O -5H O: found 383, theory 382; inflec tions at pH of 5.5, 8.7and 11.25.

Total N values determined by Kjeldahl:

(B) C H N O percent N: found was 9.51; theory 9.59 (C) C H N O -5H O,percent N: found was 7.34;, theory 733. V

A 269.5 g. sample of EDDS-4H-2H O (0.8216 mole) was dried at 95 C. to aconstant Weight. The 28.5 g. (1.583 moles) loss of water corresponds tothe theoretical loss from the dihydrate.

The reactions were usually carried out in metal reactors, preferablystainless steel, in order to avoid contamination by glassware. Theconditions described were designed from the viewpoint of simplicity,economy, and convenience, but departure from these conditions may betolerated Without detrimental elfects.

The quantity of solvent water, time of reaction, pH of precipitation,and total time of precipitation may all be varied, somewhat, without anyserious drop in product yield.

The rate of formation of EDDS-4H by the procedure described in Example Iwas determined by periodic isolation of product during the over-allreaction time. Table I below shows the quantity of product whichapproaches a maximum value:

When the yield of EDDS-4H is plotted against the log of the reactiontime, a straight line is obtained. Extrapolation to 100% yield shows theobtaining of the theoretical yield after 155 hours of refluxing.

The true amphoteric nature of these polyamino polycarboxylic acids isshown by their ability to form salts with mineral acids.

EXAMPLE II Ethylenrzdiamine Bfs-N,N-Succinic Acid Dihydrogen SulfateGH1NCHCOOH:I H2804 HgOOOH a H ---CH21GCH3COOH] SO4- H HZOOOH 40 grams ofethylenediamine bis-N,N'-succinic acid (0.144 mole) were added to .100g. of 98% sulfuric acid, The mixture was kept below 30 C. in an ice bathand stirred so as to form a solution. The solution, when diluted at roomtemperature with 100 ml. of H 0, formed a white microcrystallineprecipitate. The product was collected on a sintered glass funnel, andthen dried several days in a vacuum desiccator. A yield of 30 g. wasobtained.

Analytical data.C H N O S, percent N: found 6.86; theory 7.18. Molecularweight determined by pH titration: found 391; theory 392; inflections atpH of 3.0, 5.5, 8.5 and 11.25.

EXAMPLE III Ethylenediamine Bis-N,N'-Su'ccinic Acid Dihydrochloride HCHgCH-OOOH] 21101 HzCOOH g hydrochloric acid at room temperature to forma solution. After several minutes, a fine white crystalline precipitatetion: found 373; theory 365; inflections at pH of 5.5,

8.5 and 11.25..

Ethylenediamine bis-N,N'-succinic acid. may easily be converted to anester as shown. a

H CH GOOH 11+ I: I?! omoooomcur A 146 g. 0.5mm sample of EDDS-4H in 400m1. of ethanol was treated dropwise with g. of concentrated H 50 Theadmixture was refluxed for 7 hours (a solution was formed after 4hours). The clear liquor was diluted with ethanol, at 20 C., to 750 ml.and 168 g. (2 moles) of NaHCO were added thereto. The slurry wasfiltered and washed with 100 ml. of ethanol. The combined liquor wasagain filtered with norite carbon and concentrated in vacuo at 80 C. Theviscous, strawcolored syrup was soluble in water, alcohol, and acetone.The yield was 200 g. of crude product, which is 99% of theoretical yieldof 202 g.

In addition to forming salts with acids, these amphoteric amino acidsalso form crystalline salts with suitable bases. The disodiumdih-ydrogen salt forms a crystalline product; however, the tetrasodiumsalt is extremely soluble and hygroscopic.

EXAMPLE IV Disodium Ethylerrediamine Bis-N,N'-Succinute L 11,0 OOH i LomoooH 2 86.9 grams of ethylenediamine bis-N,N-succinic acid (0.3 mole)were added to 50 ml. of Water, then dissolved by the addition of 59.2ml. of 10.07 N NaOH (0.6 mole). The slurry was heated to form asolution, which was allowed to cool slowly. The product was filtered asdry as possible in vacuum. The white crystalline product wasrecrystallized from 200 ml. of water. The yield was 32.6 g., 32% of thetheoretical 100.9 g. (anhydrous) yield. I

One-half of the above product was dried at C.

- and was analyzed.

Analytical data.C H N O Na -4H O, percent N: found 6.71; theory 6.81. CH N O Na percent N: found 8.13; theory 8.33. Molecular weight by pHtitration: EDDS-2Na-4H O, M.W.: found 411; M.W.: theory 408. EDDS-2Na,M.W.: found 342; M.W.: theory 336.

EXAMPLE V H [oHn IoHoooH:| 2NH3OH 89.6 grams of ethylenediaminebis-N,N'-succinic acid (0.307 mole) were added to 50 ml. of water, thendissolved with 40 ml. of concentrated NI-I OH (29% by weight NH whilestirring and heating. When the solution was cooled to 0 C., a large cropof White crystals formed. These crystals were filtered, washed with 4ml. of water and filtered dry on a Buchne'r funnel. The

7' product was air dried to a constant weight. The product Weighed 65.6g., 65.6% of the theoretical 100 g. yield.

Analytical data.C H N O -2H O, total percent N: found 15.27; theory15.47. Percent N as free NH found 756; theory 7.73.

While ethylenediamine bis-N,N'-succ-inic acid has been found to bestable in boiling alkaline or neutral solutions, prolonged boiling atits isoelectric point does result in a change.

The preparation of ethylenediamine bis-N,N-succinic acid is not limitedto the use of maleic acid as the starting material. With littlemodification, the trans isomer, fumaric acid is easily substituted.

EXAMPLE VI Ethylelzediamine Bis-N,N'-Succinic Acid (EDDS-4H) CH-COONaCH2NHz A 2Nn0 o-lin H NH EOE 232 grams of fumaric acid (2.0 moles) wereadded to 200 ml. of water, and the mixture was stirred. 320 grams of 50%by weight of NaOH (4.0 moles) were added to the reaction mixture. Again,the exothermic reaction required moderate cooling (80 C.), a refluxcondenser, and good agitation. The reaction suspension was treated with70 g. (86% by weight) of ethylenediamine (1.0 mole) diluted with 300 m1.of water, and was refluxed 56 hours. The partially soluble disodiumfumarate gradually dissolved as it was consumed in the reaction.

The final clear reaction solution was cooled, then acidified to a pH of2.0 with 360 m1. of concentrated HCl. When no further product separatedfrom the solution (8-16 hours), it was filtered, washed with severalportions of water, and dried to a constant weight at 100 89.6 grams ofethylenediamine bis-N,N-succinic acid C. Yield: 220 g., 75% of theory(292 g.); M.P.: 220 222 C. (MP. of EDDS=4H; 220-222 C.).

The melting point of this product was not changed when admixed with thecrystalline product of Example I, which identifies the product made withfumaric acid as being the same as that made with maleic acid.

While KOH may be freely substituted for NaOH in the preparativeprocedure of EDDS-4H, a volatile tertiary amine such as triethylaminecan be used with some reservation. The lower boiling point of this aminelowers the reflux temperature, and cuts the yield to a less favorable32%. A higher boiling amine such as triethanolamine will be shown to bea favorable substitute for NaOH.

Attempts to react the secondary nitrogen of EDDS-4H with additionalmaleic groups were not successful under the mild conditions of ExampleI.

EXAMPLE VII Diethylenetriamine Bis-N,N-Succinic Acid I :I L CI-I COOH -1DETA DS Repeating the conditions of Example I, diethylenetriamine wassubstituted for ethylenediamine, as is described in the followingexample.

The reaction was carried out as described in Example I, combining 200 g.of maleic anhydride (2.02 moles) in ml. of water with 320 g. of 50% byweight NaOI-I. This solution was then treated with 103 g. ofdiethylenetriamine (1.0 mole) and was refluxed for 48 hours. Thereaction mixture had to be diluted to 800 ml. during the reflux periodso as to keep the reactants and product in solution.

The reaction solution was cooled and then acidified with 320 ml. ofconcentrated I-ICl to a pH of 3.3. Upon setting overnight, the product,a fine white microcrystalline product, was filtered and washed with two,100 ml. portions of water. This material was dried at 100-105 C. to awhite free-flowing powder. Yield: g., 57% of theory (335 g.); M.P.:208210 C.

The sample of diethylenetriamine bis-N,N"-succinic acid wasrecrystallized in the normal manner, that is, by dissolving it first inNaOH solution, followed by reprecipitation in the cold at a pH of 3.3with concentrated I-ICl. The resulting product was filtered and washedthoroughly with water. The product was divided into fraction (A) whichwas air dried to a constant weight and fraction (B) which was dried at100 C. to a constant weight.

The series of polyethylene polyamines was continued with the nextmember, triethylenetetramine. Since the product is water soluble, amodification in procedure for isolating the product was required.

EXAMPLE VIII Triethylenetetramine Bis-N,N-Succinic Acid CH-COONa 2 I A011 NCH 0 1 NH H OON I 2 2 l 2 2)2 (EHzCO ONDiIz i I I -CHgNCHgCHgN-CHCO 011 TEDADS The reaction was carried out in the same manner describedin Example I, that is, by combining 200 g. of maleic anhydride (2.04moles) in 100 ml. of H 0 with 320 g. of 50% by weight NaOH. The solutionwas treatedwith 146 g. of triethylenetetramine (1.0 mole) and wasrefluxed for 48 hours.

The reaction solution was filtered, cooled, and diluted to 1 liter. Thiscorresponds to a 1 molar solution of tetrasodium triethyienetetraminebis-N,N-succinate. A 100 ml. (0.1 mole) aliquot was acidified with 25ml. of concentrated HCl, but did not yield any precipitate.

Another 100 ml. (0.1 mole) aliquot of the tetrasodium salt was passedthrough Amberlite lR-lOO cation exchange resin (acid form). The 800 ml.of acidic efiluent were concentrated under vacuo to a syrup. The syrupwas further dried by washing with ethanol, and desiccation for severalweeks. The brown product hardened to a friable brown solid. This brownsolid was insoluble CHOOONa 9 in ethanol or acetone, but soluble inwater. The product was very hygroscopic.

A 2.8227 g. sample of desiccated product was dried to constant weight inan oven kept at 100 C. The sample fused, foamed, and finally hardened toa brittle spongelike mass. The 0.2098 g. loss of water left 2.6129 g. ofanhydrous material. This loss corresponds closely to a dihydrate.

Analytical data.-C H O N percent N: found 13.73; theory 14.80.

The next in the series of polyethylene polyarnines,tetraethylenepentamine, reacted similarly. The brown, hygroscopic aminoacid was prepared by the following procedure.

' EXAMPLE IX Tetraelhylenepentamine Bis-N,N Succinic Acid 1rHN(CH2CH2I1ICHZOH2NH2)2 A' HC 0N9,

H HN CH2CHzI ICHgCHgNCH-COOH] HZCOOH z The reaction was again carriedout in the same manner described in Example I, that is, by combining 200g. (2.04 moles) of maleic anhydride in 100 ml. of water with 320 g. of50% by weight NaOH. The hot solution was treated with 189 g. (1.0 mole)of tetraethylenepentamine, and was then refluxed for 28 hours.

The final reaction solution was cooled, filtered, diluted to 1 liter andstored as a 1 molar solution of tetrasodium tetraethylenepentaminebis-N,N -succinate. Since acidification does not liberate the watersoluble free acid, a 0.1 mole aliquot (100 ml.) of the tetrasodium saltwas passed through a column of Amberlite IR-100 cation resin (acidform). The 800 ml. of acidic effluent were concentrated under vacuo to asyrup, which was washed with ethanol and desiccated for several daysuntil it solidified. The brown solid was insoluble in ethanol andacetone, but soluble in Water. The product was very hygroscopic.

A 4.9871 g.'sample of dessicated acid was dried to constant weight at100 C. The product fused, foamed, and then hardened to a brittle mass.The 0.5713 g. loss of water left a 4.415 8, g. residue. This would bethe theoretical loss from a trihydrate.

Analytical dam.-C H O N percent N: found 14.72; theory 16.61.

The next example incorporates a polyamine of a differentnature,specifically one which contains a 6-carbon chain between the aminogroups.

EXAMPLE X Y 1,o-Hexamethylenediamine Bis-N,N'-Succinic Acid 011-0 0 O Na1 F i CHQGHZOH2N H COOH L rncoon' 2 The reaction was carried out in thesame manner as described in Example I, that is, by combining 100 g. of

1.0 maleic anhydride (1.02 moles) in 200 m1. of water with 160 g. of 50%by weight NaOH. The hot solution was then treated with 58 g. (0.5 mole)of 1,6-hexamethylenediamine, and was refluxed for 48 hours.

The final liquor was cooled, and acidified with 160 ml. of concentratedHCl to a pH of 2.6. The white crystalline product was allowed to settlefor several hours, and was then filtered and washed with 800 ml. ofwater. The crystals were dried to constant weight at 105 C. The yieldwas g., 64.6% of the theoretical yield of 116 g.

A 60 g. sample of the above product was dissolved in 10% NaOH, andreprecipitated by acidification to a pH of 2.6 with concentrated HCl.The product precipitated in two distinctly separate fractions.

The first crop (No. 1) of crystals separated immediately from theacidified solution. This crop was collected, washed, and dried at 105 C.The yield was 10 g., 16.6% of theory.

A second crop (No. 2) of crystals separated from the clear filtrate uponstanding for 15 minutes. The yield of dried product was 35 g., 58% oftheory. This second crop was divided into two portions: (A), which wasdried in air at room temperature, and (B), which was dried at 105 C. toa constant weight.

Analytical data of crop N0. 2:

C14H23N2032H20, percent Ni fOund theory 7.11. (213) C I-1 N 0 percent N:found 7.63; theory 7.82. M.W. determined by pH titration: found 328;theory 348. Inflection pH was 7.0. 0

Crop No. 1 appeared to be the product formed by an impurity present inthe 1,6-hexamethylenediamine, namely, 1-hydroxy-6-aminohexane. Thisprobably results from the following side reaction:

H CH-OOONa A u H0 0119mm no oHmNorr-o OONa CH-COONa H20 0 ONa HQCOOH:

This by-product may be separated from the desired bisadduct byfractional crystallization as shown above.

In the following example, a diprimary amine is utilized which contains asubstituted alkyl chain linking the primary amine groups.

EXAMPLE XI Z-Hydroxypropylene-J,3-Diamine Bis-N,N-Succinzc Acid OH NHz AI'- 111 1 H-0H HOCH--CHiNCE-OOON& HgNHg L H 00 ONa orr-oooNa HCOONa Lorrzooorr The reaction was carried out as described in Example I, thatis, by combining 200 g. of maleic anhydride (2.04

moles) in 400 ml. of water with 330 g. of 50% by weight NaOH. Thesolution was then treated with g.,of2-

hydroxypropylene-1,3-diamine (1.0 mole), and was then refluxed for 60hours.

The reaction solution was diluted to 1.5 liters with water, filtered,cooled to room temperature andthen to an amber oil (volume:approximately 450 Inl.). This product was washed with 500 ml. of acetoneand then EXAMPLE YII Barium Dihya'rogen EthylenediamineBis-N,N'-Succinate CH NCHCOONa 132.01;

| L CHzCOOH The barium dihydrogen salt is readily obtained from anaqueous solution.

29.2 g. of ethylenediamine bis-N,N-succinic acid (0.1 mole) weredissolved in 200 ml. of H containing 8 g. of NaOH (0.2 mole). Thesolution was stirred and rapidly treated with 100 ml. of 1.0 molar BaCl(0.1 mole). The insoluble salt separated after a short period. Aftersettling for 1 hour, the mass was filtered, washed with 100 ml. of waterand dried at 110 C. to a constant weight. The 40 g. yield was 93.5% ofthe theoretical 42.7 g. yield.

Analytical data.C I-I N O Ba, percent N: found 6.44; theory 6.56.

A lead dihydrogen salt was similarly prepared from lead acetate solutionand ethylenediamine-N,N-bis-succinic acid.

Aconitic acid was utilized in order to show the adaptability ofunsaturated tricarboxylic acids to this process.

The substitution of triethanolamine for NaOH as neutralizing base isalso described in the following example.

EXAMPLE XIII Diethylenetriamine Bis-N,N"-Tricarballylic Acid fiH-C OOTea -COOTea I-IN(CH GH NH H 0 0 OTea L H C OOH DETDT 174 grams ofaconitic acid (1.0 mole) were treated with ml. of water, followed by 450g. of triethanolamine (3.0 moles) and, finally, 51.5 g. ofdiethylenetriamine (0.5 mole). The thick mixture was then set aside todigest under gentle reflux at 125130 C. for 36 hours.

The reaction solution, a dark red-brown syrup, was diluted to 1 literand was used as a 0.5 molar solution of the product.

A 200 ml. (0.1 mole) aliquot of the reaction solution were treated with24 g. (0.6 mole) of NaOH and 1 liter of ethanol. Prolonged stirring gavea-thick oily sediment of hexasodium salt, which was washed free oftriethanolamine with two, ml. portions of ethanol and was dissolved in200 ml. of water. This solution was H CIlzCOOTGQ] 2 passed through acolumn of Amberlite IR-lOO cation exchange resin (acid form). The acidiceffluent was concentrated under vacuo to 65 ml., then treated with 800ml. of ethanol. A brown solid separated, which was dried in a vacuumdesiccator. The yield was 8 g., 21% of theoretical 33.8 g. yield. Itsdecomposition point was approximately 230 C.

Analytical data.C H N O percent N: found 10.91; theory 9.31. M.W.determined by pH titration: found 447; theory 451. Infiections at pH of6.8 and 10.5.

The position of adduction of the primary amine to the unsaturation ofaconitic acid may be either a or (3. Possibly the beta isomer maypredominate.

H20 0 OH and/ or CH COOTea] z 174 grams of aconitic acid (1.0 mole) weretreated with 40 ml. of water, followed by 450 g. (3.0 moles) oftriethanolamine (TEA) and, finally, 58 g. (0.5 mole) ofhexamethylenediamine. This mixture was then set to digest under gentlereflux at 125-130 C. for 36 hours.

The reaction mixture, a dark red-brown syrup, was diluted with water to1 liter and was used as a 0.5 molar solution. Acidification of a sampleof this solution precipitates the free acid as an oil; however, it isquite unstable in air and soon auto-oxidizes to a black resinous mass.Thus, it was considered more feasible to prepare one of its metal salts,in this case, the trizinc salt.

EXAMPLE XV A ml. (0.05 mole) aliquot of the above reaction solution ofExample XIV was diluted with 100 ml. of water. The solution was thentreated, while stirring, with 150 ml. of 1 molar ZnCl solution. Thereaction mixture had a pH of 7.3. The product was filtered, wassequentially washed with 200 ml. of water and 100 ml. of ethanol, andwas then dried to a constant weight at -130 C. The yield was 20 g., 63%of the theoretical 32.5 g. yield.

Analytical data on Zn salt.C H N O Zn percent N: found 4.06; theory4.28.

The reactivity of aliphatic primary amines has been conclusively shownin the previous examples. The next step incorporated aromatic polyaminesinto our process. The expected difiiculty was encountered with theseadducts, that being the tendency of the free amino acids to oxidize inopen air. Because of this, the adduct was identified after conversion toa suitable metal salt.

EXAMPLE XVI p-p-Methylenedianiline Bis-N,N-Succinic Acid .H.{@ t t..m...l

E 01120 O OH MDDS The aryl amine incorporated into this reaction iswater insoluble, as well as being insoluble in any alkaline aque ousmedia. Thus, triethanolamine was again used as both solvent andneutralizing base.

100 grams of maleic anhydride (1.02 moles) were added to 25 ml. of waterand allowed to hydrolyze slowly to maleic acid. The mass of crystalswere gradually dissolved in 330 g. (2.2 moles) of triethanolamin.Finally, 99 g. (0.5 mole) of p,p'-methylenedianiline were added and thereaction mixture digested under reflux at 130- 140 C. 'for 26 hours. Thereaction solution remained as one clear phase.

The solution was cooled and diluted with 250 ml. of water. Since thereaction solution remains as one phase,

. this is evidence that the amine has reacted, otherwise it would haveseparated on dilution.

The diluted solution Was acidified with 183 ml. of concentrated HCl (2.2moles). A gray'oil separated immdiately and was decanted free of themother liquor. This residue was washed with 200 ml. of water, dissolvedin 280 ml. of water containing 80 g. (2.0 moles) of NaOH, andrepre'cipitated with 166 ml. of concentrated HCl (2.0

moles). The residue was again decanted free of mother liquor, washedwith three, 200 ml. portions of water and two, 150 ml. portions ofethanol. The free acid solidified when desiccated; however, the surfacesturned red when exposed to air, evidencing oxidation. The yield was 150g., 70% of the theoretical 215 g. yield.

Dizinc p,p-Methyl enedianiline Bis-N,N-Succinate' CH C O ONa 43 grams ofp,p'-methylen'edianiline bis-N,N-succinic acid (0.1 mole) were dissolvedin 120g. of water containing 16 g. (0.4 mole) of NaOH. The solution wasfiltered with Norite carbon and was then treated while stirring with 200ml. of 1 molar ZnCl solution for 1 hour."

polyamine with another type of unsaturated acid, displays a phenomenonwhich occurs when the resultant secondary amine is 'y to a carboxylgroup. An intramolecular cyclization takes place upon acidification,resulting in a pyrrolidone derivative.

l 4 EXAMPLE XVII Diphenylmethane p,p-Di-N-Pyrr0lid0ne-2,4-

. Carboxylic Acid H 00 OTea i /OHzCH-O O OH L H.

120 grams of itaconic acid (0.92 mole) were added to 10 m1. of water,and the resulting salt was treated with 300 g. of triethanolamine (2.0moles). The slurry was heated and stirred until completelydissolved. Theresultant viscous solution was treated with 91 g. of p,p'-methylenedianiline (0.46 mole) and digested under gentle reflux at120-130 C. for 48 hours. The reaction mixture, which contained someinsolubles, was diluted to 600 m1., and filtered through a pad ofdiatomaceous earth. The clear filtrate was then acidified with 165 ml.of concentrated HCl. The oil, which separated, was decanted free ofmother liquor, washed with two, 100 ml. portions of water, and was thenredissolved in 250 ml. of Water containing g. (2.0 moles) of NaOH. Theproduct was reprecipita-ted with 165 ml. of concentrated HCl (2.0 moles)washed with two, ml. portions of water, and was then dried in a vacuumdesiccator for several days. The final product was a dark-browncrystalline mass. The yield was 40 g., 21% of the theoretical 194 g.yield. The melting point was 200-210 C.

Analytical data.C H N 0 percent N: found 6.92; theory 6.64. M.W.determined by pH titration: found 458; theory 422. Inflections at pH of9.0. 7

EXAMPLE XVIII a,a'-Diamino, m-Xylene-N,N'-Disuccinic Acid r lrnNn,

CHOOONa II CHCOONa l oH,NoH-o OONa H orno o ONa H2NCHCO ONa HY crnoo ONaCH COO ANaCl H Ca I CH N-OH-OOO H Ca CHQCOO/ H CH COOH 210 grams of thedicalcium salt (0.95 mole) were slurried with 1 liter of water. The 120g. of oxalic acid dihydrate (0.96 mole) were added and stirred therewithfor hours. The white slurry was filtered, and washed with 300 of water.The combined mother liquor and washings were then evaporated to 400 ml.(at room temperature). The residual syrup was treated with 500 ml. ofacetone. The oily residue was then washed with two, 500 ml. portions ofacetone and a 500 m1. portion of ethanol. The final semi-solid was driedin a vacuum oven at 90 C.; it foamed. The friable mass was crushed andfurther dried to constant weight. The over-all product, a pale yellowmass, was water soluble and non-hygroscopic. The melting point was 155C.

Analytical data.C H N O percent N: found 7.79; theory 7.61. M.W.determined by pH titration: found 362; theory 368. Infiections at pH of6.5 and 11.25.

The series of amino acids which may be obtained from the union of polyprimary amines with unsaturated polycarboxylic acids can be seen asnearly limitless The examples shown are intended to illustrate ourinvention and should not be interpreted as limiting it.

The utilization of the products of our process are varied and numerous.Many of its outstanding uses are based upon its unique properties as achelating compound. Some of the ions successfully tested are shownbelow. In the test, a ml. sample of 0.1 molar chelate was added to 50ml. of water treated with 10 m1. of 0.1 molar of the metal ion and 1 ml.of precipitant such as saturated Na l llo or oxalic acid. The solutionwas adjusted to the recorded pH. The solution was studied in the coldfor 1 hour and was then boiled. All solutions below remained clearthroughout.

*Identilied by initials assigned to formulas in the various examples.

The orelates of the amino acids were in some cases quite easily preparedin a pure form. The procedure be low may be used for many of the aminoacids, and many metal ions.

EXAMPLE XIX Cupric Dihydrogen Ethylenediamilze Bis-N,N-

29.2 grams of ethylenediamine bis-N,N'-succinic acid, EDDS-4H (0.1 mole)were mixed with 25 1111. of water that was treated with 20 g. of cupricacetate monohydrate (0.1 mole). The admixture was warmed and stirred toform a solution. When the blue liquor was diluted with 200 ml. ofethanol, the water soluble cupric chelate of ethylenediamine bis-N,N'-succinic acid separated out. This was filtered and dried to provide anearly quantitative yield of the product. Recrystallization of theproduct from water and ethanol yielded a purified product.

The crystalline manganous dihydrogen chelate of EDDS was preparedanalogously except that 24.5 g. of

manganous acetate tetrahydrate was used instead of 20 g. of cupricacetate monohydrate.

Analytical data.-Cu H chel ate (from Cu (C H O C H N O Cu; percent N:found 7.82; theory 7.90. Mn l-l chelate (from Mn(C H O C H N O Mn;percent N: found 7.58; theory 8.12.

These and other metal chelates of the new bis-adducts of this inventionare relatively soluble in water and have utility as a source of normallyinsoluble metal compounds in soluble form. As such they may be used assources of trace elements in fertilizer mixtures, insecticide formulas,etc.

EXAMPLE XX The new bis-adduct compound described in the above exampleshave been found to be quite effective in removing rust and oxidecoatings from metal surfaces at pH values below about 9.0 in aqueoussolutions containing a reducing agent such as a sulfite, hyposulfite,sugar hydroquinone, etc. For example, uniformly rusted iron (aged)strips were immersed for three hours (without agitation) at C. in acleaning solution having the formula:

Bis adduct compound grams 15.0 Sodium bisulfite (58.5% S0 do 7.5 Water,suflicient amount to form a 300.0 ml. soln.

The pH of the solution was adjusted to 8.0 with NaOH.

The weight of the rust lost from the 81.6 sq. cm. surface of the metalstrips and the condition of the resulting metal surfaces were noted asfollows.

TABLE III Examples Compounds Wt. of Rust Results Lost (g.)

I H I OH1 I--OHCOOH b. 589 Clean surface, 15v L H20 0 OH I 11151; spots.

I- H vII HN-CH1CHzI IOHCOOH b.697 Do.

I. 0320 0 OH 2 l- H H vIII --cHzI- I-oH,oH,I- I-(mo 0 OH 6. 072 Do.

I. omo 0 OH H H IX I- HN-oH2oH,-1 IoH,oH,1 IoIIoo0H o. 754 Clean.

L CH2C 0 OH 2 l' H x; -1 oinomoni i fincoon oi 112s M11111 r1121i'fiaifis'; L V 6 OH I XI keenwake "1i 1. on 01152116211111 action).

XIII mr emcmwcebofi o. 050 Spotted rust.

L 011200 0H1 Ir- H CHECOOH omiwbfioo OH XVIII 0. 531 Do.

H Ha r-b15100 OH 121m: 0. 0 343 Rizsty.

When the test strips were freshly fusted (36 hours) with a 5% NH C1solution, the removal of rust was much rapid {and complete. Under thesame conditions the re- 'sults a're tabulated below.

TABLE IV Examples Combounds Wt. of Rust Results Lost (g.)

I'- H I -CHI1ICHOOOH 1.249 Clean.

L omcoofi 11 VII finT-omoml korrooog 0.911 sg oged rust (rinsed0111000121 2 II 11 VIII --ofi;1 i oHgoHz1 -I-o11c0o11 1.151 Clean.

H H IX HN- -oI'IIoH,-1 rcH,cHz1 1- 0HcooH 0.992 Do.

I- V 7 H X -CHZCHQCH I I-CE@6OH 0.579 Largerust spots.

L moooH 2 I- H X'I fi66fiofiI I-ofioo0fi 1.281 Clean (rapid action).

1 mcoon 2 TABLE IVContinued Examples Compounds Wt. of Rust Lost (g.)

Results H onto on HNOHnOHzN-CC 0 on L CHzC O OH 2 mm-01100 OH XIII XVIIII OHaN-CHCOOH CHQCOOH 0.105 Rusty.

0. 763 Clean.

The above compounds show excellent rust removal The pH of the solutionwas adjusted to 11.5 with NaOH capability.

The addition of the above adduct amino acids to alkaline solutions, suchas sodium carbonate or phohphate, speeds the cleaning or etching ofaluminum. Test solutions were prepared containing the followingingredients:

at C.

A Reynolds 3S-H-14 aluminum test strip of 30.1 sq. cm. surface area wasimmersed in each solution for hour. The results are tabulated below.

The addition of the new adduct acid compounds to solutions of strongmineral acids was found to greatly A i id 4 decrease the acid attack onplain iron. 0.5%, 1.0% Trisodium phosphate crystal 2 and 3% y w samplesin z 4 at Water, sufficient amount to form a 200 m1. soln. were testedon a 7 x 4.5 x 0.5 cm. strip of lIOIl for five 30 hours. The followingresults were produced.

TABLE V Examples Compounds Wt. of Al. I.P.Y.

Lost (g.) 5 hr.

H I CHgl I-OHCOOH 0.101 8.14

i. CHQCOOH 1 H v11 ran-omonnh-onooon 0.0965 7.73

L 011100011 2 H VIII -oH21 I-oH2oHz1 I-o11oooH 0.118 9.47

i. CHzCOOH a I'- H H IX HNCH2OH2-1 IOH;CHgI ICHCOOH 0.055 4.42

i. omoooH 2 I" H X CHzOHzCH2I T-CHCOOH 0.038 3.01

L CHnCOOH 2 F H XI H0oHcH2I IoHo00H 0.005 7.50

L CHaCOOH 2 I- H omoooH XIII HN-OHzOHgN-iJ-OOOH 0.077 6.17

i. ongooou 7 H OHzCOOH (fHzN-CHCOOH XVIII o. 044 a. 53

CHzN-CHCOOH Blank o. 026 2.08

When the solutions were later lowered to a pH 8.5, they all deposited awhite floc exee t the 2-h dro ro-- pylene-1,3-d1amme b1s-N,N-suee1nicacid, which displays its superior sequestration of luminum xyp TABLE VIExamples Compounds Steel I)? (g') H I -oHn r-o11o OH 0.112 0. 071 0. 055

L (H2 o 0 OH 1 I- H VII HN-CHzOH ILFCHCOOH] 0.02s 0. 01s 0. 012

L (31120 0 OH 1 l' H VIII -CHgII-CHzOH;ILT-OHO 0 on ll 0. 074 0. 03s 0.024

L ame 0 0H 1 p I- H H IX nN- ofiion. i roniofin r-ofio 0 OH :I 0.063 0.026 o. 015

L (E1110 0 OH 2 I H X -omomormh-onooon o. 072 o. 048 0. 020

L CHzC 0 0H I- H XI HOOH-CHzI IOHCOOH] 0.09s 0. 01s

L omo 0 on a I- H 011,00 0H xm HN-CH1OH2NC-C 0 OH :I 0. 025 o. 022 '0.011

L une 0 0H 2 E 01120 0 on omN-on c 0 on XVIII H 0.087 0. e69 g Hali-"CHO 0 OH 01120 0 OH Blank... 0.19s

The results which are underlined represent data from by weight, foamswere obtained which were stable for solutions where the added adductacid was incompletely dissolved.

EXAMPLE XXI The soap-acid amines form. amides with EDDS -adducts toyield compounds of interest. Armeen OD, a-mixture of high molecularweight amines (Armour and Co.) with oleyl amine predominatory, was fusedwith ethylenediamine bis-N,N'-succinic acid.

53 grams of Armeen CD (0.2 mole) were treated with 29.2 g. ofethylenediamine bis-N,N'- succinic acid (0.1 mole). The mixture waswarmed slowly with stirring to 160 C. and kept at this temperature(under a short air condenser) for one hour. The liquor was cooled,dissolved in 250 ml. of ethanol, and was filtered free of insolubles.The liquor was then heated free of ethanol in a vacuum oven at 80 C. Theproduct, a clear brown viscous liquid, weighed 75 g. a The product ofthis reaction is an eifective wetting and foaming agent suitable for usein cleaning and ore flotation operations. In concentrations of less than0.25%

30 minutes or more. These foams were formed in alkaline (pH of 10),neutral, and acid (pH of 1.5 or less) solutions. Armeen OD itself formsstable foams in acid and neutral solutions, but in alkaline solutions itdeposits much insoluble amine.

Similar results were obtained With Armeen CD, and coco oil base amine,the latter also being a product of Armour and Co.

These soap-acid amides are soluble in ethanol, chloroform, benzene andkerosene, but are almost insoluble in water and acetone. One g. ofcompound was tested with 25 g. of solvent.

EXAMPLE XXII A water-soluble polymer may be prepared by the fusion ofethylenediamine bis-N,N'-succinic acid with urea.

F ---OH N-CHC OOH 4Urea Polymer HQCOOH 2 grams of urea were melted at-l40 C. and were then treated in small portions with 146 g. ofethylenediamine bis-N,N'-succinic acid (0.5 mole) while stirring theliquid mass to keep down the foam. When foaming had diminished (aftersome 2 hours of heating) the heating was discontinued. The clear ambersyrup was cooled and thereby hardened to a brittle amber glass. Theglass was hygroscopic and water soluble. The residue totaled 244 g., aloss of 22 g.

This product may be incorporated into urea and other resin formulationsas a modifier.

A titration curve showed two inflections, at a pH of 6.0 and 11.0 Themolecular weight was calculated as 415 g. This corresponds closely to aratio of one mole of ethylenediamine bis-N,N'-succinic acid to two molesurea molecules. The pH of an aqueous solution of the polymer was foundto be 6.92.

Because of their general chelating and metal solubilizingcharacteristics and the reaction characteristics with other organiccompounds the new compounds of this invention may readily suggestthemselves for uses not enumerated above.

The foregoing detailed description has been given to clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

We claim:

1. A compound selected from the group consisting of:

(a) a compound of the formula:

wherein Z and Z are saturated acyclic bis-adduction groups derived fromthe class consisting of lower alkenyl, 1,4 conjugated polycarboxylicacids having at least 2 and not more than 3 carboxyl groups, and saltsthereof and R is a member of the class consisting of lower alkylene,phenylene-lower alkylene-phenylene, lower alkylene-phenylene-loweralkylene, and

lower alkylene-ll -lowcr alkylene H groups; (b) chelates of the compoundof (a) and a polyvalent metal ion; and (c) esters of the compound of (a)and a lower alkanol. 2. A compound of the formula:

wherein Z and Z are saturated acyclic bis-adduction groups derived fromthe class consisting of lower alkenyl, 1,4 conjugated polycarboxylicacids having at least 2 and not more than 3 carboxyl groups, and saltsthereof and R is a member of the class consisting of lower alkylene,phenylene-lower alkylene-phenylene, lower alkylenephenylene-loweralkylene, and

lower ulkylenelTI-lower alkylenc 4. The product:

i i N (lower alkylene-N-lowor alky1ene)-N HOgG- H H- C 0 H HOzO- I H H ICO;H H H 5. The product I (lower alkylenc-N-Iower alkylene)bis-N,N'-tricarballylic acid.

6. The product:

wherein n is a positive integer of not less than 1 and not more than 2and R and R are lower alkylene groups when n is 1.

7. The product:

1 L (lower alkylene-phenylene-lower alkylene) H03C- H H C 0 11 HOgO- -HH- --O 0 11 8. Chelate of a compound of claim 2 and polyvalent metalion.

9. Ester of a compound of claim 2 and lower alkanol.

10. Metal salt of the product of claim 3.

11. Chelate of the product of claim 3 and polyvalent metal ion.

12. Ester of the product of claim 3 and lower alkanol.

13. Metal salt of the product of claim 4.

14. Chelate of the product of claim 4 and polyvalent metal ion.

15. Ester of the product of claim 4 and lower alkanol.

16. Metal salt of the product of claim 5.

17. Chelate of the product of claim 5 and polyvalent metal ion.

18. Ester of the product of claim 5 and lower alkanol.

19. Metal salt of the product of claim 6.

20. Chelate of the product of claim 6 and polyvalent metal ion.

21. Ester of the product of claim 6 and lower alkanol.

22. Metal salt of the product of claim 7.

23. Chelate of the product of claim 7 and polyvalent metal ion.

24. Ester of the product of claim 7 and lower alkanol.

25. The method of producing bis-adduction products comprising reactingan organopolyprimary amine with one mole of a member from the groupconsisting of lower alkenyll, 1,4 conjugated polycarboxylic acids havingat least 2 and not more than 3 carboxyl groups, salts thereof and loweralkyl esters thereof for each primary amine group present in theorganopolyprimary amine.

26. The method of producing bis-adduction products comprising reactingin an alkaline medium anorganopolyprimary amine with one mole of amember from the group consisting of lower alkenyl, 1,4 conjugatedpolycarboxylic acids having at least 2 and not more than 3 carboxylgroups, salts thereof and lower alkyl esters 25 thereof for each primaryamine group present in the organopolyprimary amine.

27. The method of producing bis-adduction products comprising reactingin an alkaline medium an organopolyprimary amine with one mole of amember from the. group consisting of lower alkenyl, 1,4 conjugatedpolycarboxylic acids having at least 2 and not more than 3 carboxylgroups, salts thereof and lower alkyl esters thereof for each primaryamine group present in the organopolyprimary amine, and adding acid tothe resulting product to form an acidic bis-adduction product.

28. The method of producing a chelate of a bis-adduction productcomprising reacting an organopolyprimary amine with one mole of a memberfrom the group consisting of lower alkenyl, 1,4 conjugatedpolycarboxylic acids having at least 2 and not more than 3 carboxylgroups, salts thereof and lower alkyl esters thereof for each primaryamine group present in the organopolyprimary amine to form a'bis-adduction product, and adding a polyvalent metal to said product toform a chelate.

References Cited in the file of this patent UNITED STATES PATENTS2,195,974 Reppe Apr. 2, 1940 2,532,391 Bersworth Dec. 5, 1950 2,761,874Bersworth et a1 Sept. 4, 1956

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (A) A COMPOUND OFTHE FORMULA: